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Modern Extortion: Detecting Data Theft from the Cloud

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20
Sep 2022
20
Sep 2022
Now one of the most popular talking points in the security world, the ransom industry continues to see growth. First ransomware, then double extortion and now simple data theft have been used to meet threat actors’ extortion needs. This blog highlights an example of this in a US customer’s SaaS environment.

Ransomware Industry

The ransomware industry has benefitted from a number of factors in recent years: inadequate cyber defenses, poorly regulated cryptocurrency markets, and geopolitical tensions have allowed gangs to extort increasingly large ransoms while remaining sheltered from western law enforcement [1]. However, one of the biggest success stories of the ransomware industry has been the adaptability and evolution of attacker TTPs (tactics, techniques and procedures). The WannaCry and NotPetya attacks of 2017 popularized a form of ransomware which used encryption algorithms to hold data to ransom in exchange for a decryption key. Last year in 2021, almost all ransomware strains evolved to use double extortion tactics: holding stolen data to ransom as well as encrypted data [2]. Now, some ransomware gangs have dropped encryption entirely, and are using data theft as their sole means of extortion. 

Using data theft for extortion is not new. In 2020 the Finnish psychotherapy center Vastaamo had over 40,000 patient records stolen. Impacted patients were told that their psychiatric transcripts would be published online if they failed to pay a Bitcoin ransom. [3]. A later report by BlackFog in May 2021 predicted data theft extortion would become one of the key emerging cybersecurity trends that year [4]. Adoption of offline back-ups and endpoint detection had made encryption harder, while a large-scale move to Cloud and SaaS platforms offered new vectors for data theft. By moving from data encryption to data exfiltration, ransomware attackers pivoted from targeting data availability within the CIA triad (Confidentiality, Integrity, Availability) to threatening data confidentiality.

In November 2021, Darktrace detected a data theft incident following the compromise of two SaaS accounts within an American tech customer’s Office365 environment. The client was a longstanding user of Darktrace DETECT/Network, and was in the process of expanding their coverage by trialing Darktrace DETECT+RESPOND/ Apps + Cloud.

Attack Overview

On November 23rd 2021, an Ask the Expert (ATE) ticket was raised prompting investigation into a breached SaaS model, ‘SaaS / Access / Unusual External Source for SaaS Credential Use’, and the activities of a user (censored as UserA) over the prior week.

1. Office365: UserA 

The account UserA had been logging in from an unusual location in Nigeria on November 21st. At the time of the incident there were no flags of malicious activity from this IP in widely used OSINT sources. It is also highly probable the attacker was not located in Nigeria but using Nigerian infrastructure in order to hide their true location. Regardless, the location of the login from this IP and ASN was considered highly unusual for users within the customer’s digital estate. The specific user in question most commonly accessed their account from IP ranges located in the US.

Figure 1: In the Geolocation tab of the External Sites Summary on the SaaS Console, UserA was seen logging in from Nigeria when previous logins were exclusively from USA

Further investigation revealed an additional anomaly in the Outlook Web activity of UserA. The account was using the Firefox browser to access their account for the first time in at least 4 weeks (the maximum period for which the customer stored such data). SaaS logs detailing the access of confidential folders and other suspicious actions were identified using the Advanced Search (AS) query:

@fields.saas_actor:"UserA@[REDACTED]" AND @fields.saas_software:"Firefox"

Most actions were ‘MailItemsAccessed’ events originating from IPs located in Nigeria [5,6] and one other potentially malicious IP located in the US [7].

‘MailItemsAccessed’ is part of the new Advanced Audit functionality from Microsoft and can be used to determine when email data is accessed by mail protocols and clients. A bind mail access type denotes an individual access to an email message [8]. 

Figure 2: AS logs shows UserA had not used Firefox to access Office365 for at least 4 weeks prior to the unusual login on the 21st November

Below are details of the main suspicious SaaS activities: 

·      Time: 2021-11-21 09:05:25 - 2021-11-22 16:57:39 UTC

·      SaaS Actor: UserA@[REDACTED]

·      SaaS Service: Office365

·      SaaS Service Product: Exchange

·      SaaS Software: Firefox

·      SaaS Office365 Parent Folders:

          o   \Accounts/Passwords
          o   \Invoices
          o   \Sent Items
          o   \Inbox
          o   \Recoverable Items\Deletions

·      SaaS Event:

          o   MailItemsAccessed
          o   UserLoggedIn
          o   Update

·      SaaS Office365 Mail Access Type: Bind (47 times)

·      Source IP addresses:

          o   105.112.59[.]83
          o   105.112.36[.]212
          o   154.6.17[.]16
          o   45.130.83[.]129

·      SaaS User Agents: 

          o   Client=OWA;Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:80.0) Gecko/20100101 Firefox/80.0;
          o   Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:80.0) Gecko/20100101 Firefox/80.0

·      Total SaaS logs: 57 

At the start of the month on the 5th November, the user had also been seen logging in from a potentially malicious endpoint [9] in Europe, performing ‘MailItemsAccessed’ and ‘Updates’ events with subjects and a resource location related to invoices and wire transfers from the Sent items folder. This suggests the initial compromise had been earlier in the month, giving the threat actor time to make preparations for the final stages of the attack.

Figure 3: Event log showing the activity of UserA from IP 45.135.187[.]108 

2. Office365: UserB 

Looking into the model breach ‘SaaS / Access / Suspicious Credential Use And Login User-Agent’, it was seen that a second account, UserB, was also observed logging in from a rare and potentially malicious location in Bangladesh [7]. Similar to UserA, this user had previously logged in exclusively from the USA, and no other accounts within the digital estate had been observed interacting with the Bangladeshi IP address. The login event appeared to bypass MFA (Multi-factor Authentication) and a suspicious user agent, BAV2ROPC, was used. Against misconfigured accounts, this Microsoft user agent is commonly used by attackers to bypass MFA on Office365. It targets Exchange’s Basic Authentication (normally used in POP3/IMAP4 conditions) and results in an OAuth flow which circumvents the additional password security brought by MFA [10].  

During the session, additional resources were accessed which appear to be associated with bill and invoice payments. In addition, on the 4th November, two new suspicious email rules named “..” were created from rare IPs (107.10.56[.]48 and 76.189.202[.]66). This type of behavior is commonly seen during SaaS compromises to delete or forward emails. Typically, an email rule created by a human user will be named to reflect the change being made, such as ‘Move emails from Legal to Urgent’. In contrast, malicious email rules are often short and undescriptive. The rule “..” is likely to blend in without arousing suspicion, while also being easy for the attacker to create and remember. 

Details of these rule changes are as follows:

·      Time: 2021-11-04 13:25:06, 2021-11-05 15:50:00 [UTC]
·      SaaS Service: Office365
·      SaaS Service Product: Exchange
·      SaaS Status Message: True
·      SaaS Source IP addresses: 107.10.56[.]48, 76.189.202[.]66
·      SaaS Account Name: O365
·      SaaS Actor: UserB@[REDACTED]
·      SaaS Event: SetInboxRule
·      SaaS Office365 Modified Property Names:
          o   AlwaysDeleteOutlookRulesBlob, Force, Identity, MoveToFolder, Name, FromAddressContainsWords, StopProcessingRules
          o   AlwaysDeleteOutlookRulesBlob, Force, Identity, Name, FromAddressContainsWords, StopProcessingRules
·      SaaS Resource Name: .. 

During cloud account compromises, attackers will often use sync operations to download emails to their local email client. During the operations, these clients typically download a large set of mail items from the cloud to a local computer. If the attacker is able to sync all mail items to their mail client, the entire mailbox can be compromised. The attacker is able to disconnect from the account and review and search the email without generating additional event logs. 

Both accounts UserA and UserB were observed using ‘MailItemsAccessed’ sync operations between the 1st and 23rd November when this attack occurred. However, based on the originating IP of the sync operations, the activity is likely to have been initiated by the legitimate, US-based users. Once the security team were able to confirm the events were expected and legitimate, they could establish that the contents of the mailbox were not a part of the data breach. 

Accomplish Mission

After gaining access to the Office365 accounts, sensitive data was downloaded by the attackers to their local system. Either on or before 14th December, the attacker had seemingly uploaded the documents onto a data leak website. In total, 130MB of data had been made available for download in two separate packages. The packages included audit and accounting financial documents, with file extensions such as DB, XLSX, and PDF.

Figure 4: The two data packages uploaded by the attacker and the extracted contents

In a sample of past SaaS activity of UserA, the subject and attachments appear related to the ‘OUTSTANDING PREPAY WIRES 2021’ excel document found from the data leak website in Figure 4, suggesting a further possibility that the account was associated with the leaked data. 

Historic SaaS activity associated with UserA: 

·      Time: 2021-11-05 21:21:18 [UTC]
·      SaaS Office365 Logon Type: Owner
·      Protocol: OFFICE365
·      SaaS Account Name: O365
·      SaaS Actor: UserA@[REDACTED].com
·      SaaS Event: Send
·      SaaS Service: Office365
·      SaaS Service Product: Exchange
·      SaaS Status Message: Succeeded
·      SaaS Office365 Attachment: WIRE 2021.xlsx (92406b); image.png (9084b); image.png (1454b); image.png (1648b); image.png (1691b); image.png (1909b); image.png (2094b)
·      SaaS Office365 Subject: Wires 11/8/21
·      SaaS Resource Location: \Drafts
·      SaaS User Agent: Client=OWA;Action=ViaProxy 

Based on the available evidence, it is highly likely that the data packages contain the data stolen during the account compromise the previous month.  

Once the credentials of an Office365 account are stolen, an attacker can not only access the user's mailbox, but also a full range of Office365 applications such as SharePoint folders, Teams Chat, or files in the user's OneDrive [11]. For example, files shared in Teams chat are stored in OneDrive for Business in a folder named Microsoft Teams Chat Files in the default Document library on SharePoint. One of the files visible on the data leak website, called ‘[REDACTED] CONTRACT.3.1.2020.pdf’, was also observed in the default document folder of a third user account (UserC) within the victim organization, suggesting the compromised accounts may have been able to access shared files stored on other accounts by moving laterally via other O365 applications such as Teams. 

One example can be seen in the below AS logs: 

·      Time: 2021-11-11 01:58:35 [UTC]
·      SaaS Resource Type: File
·      Protocol: OFFICE365
·      SaaS Account Name: 0365
·      SaaS Actor: UserC@[REDACTED]
·      SaaS Event: FilePreviewed
·      SaaS Service Product: OneDrive
·      SaaS Metric: ResourceViewed
·      SaaS Office365 Application Name: Media Analysis and Transformation Service
·      SaaS Office365 File Extension: pdf
·      SaaS Resource Location: https://[REDACTED]-my.sharepoint.com/personal/userC_[REDACTED]_com/Documents/Microsoft Teams Chat Files/[REDACTED] CONTRACT 3.1.2020.pdf
·      SaaS Resource Name: [REDACTED] CONTRACT 3.1.2020.pdf
·      SaaS Service: Office365
·      SaaS Service Product: OneDrive
·      SaaS User Agent: OneDriveMpc-Transform_Thumbnail/1.0 

In the period between the 1st and 30th November, the customer’s Darktrace DETECT/Apps trial had raised multiple high-level alerts associated with SaaS account compromise, but there was no evidence of file encryption.  

Establish Foothold 

Looking back at the start of the attack, it is unclear exactly how the attacker evaded the customer’s pre-existing security stack. At the time of the incident, the victim was using a Barracuda email gateway and Microsoft 365 Threat Management for their cloud environment. 

Darktrace detected no indication the accounts were compromised via credential bruteforcing, which would have enabled the attacker to bypass the Azure Active Directory smart lockout (if enabled). The credentials may have been harvested via a phishing campaign which successfully evaded the list of known ‘bad’ domains maintained by their email gateway.  

Upon gaining access to the account, the Microsoft Defender for Cloud Apps anomaly detection policies would have been expected to raise an alert [12]. In this instance, the unusual login from Nigeria occurred over 16 hours after the previous login from the US, potentially evading anomaly detection policies such as the ‘Impossible Travel’ rule. 

Figure 5: Event log showing the user accessing mail from USA a day before the suspicious usage from Nigeria 

Darktrace Coverage

Darktrace DETECT 

Throughout this event, high scoring model breaches associated with the attack were visible in the customer’s SaaS Console. In addition, there were two Cyber AI Analyst incidents for ‘Possible Account Hijack’ associated with the two compromised SaaS Office365 accounts, UserA and UserB. The visibility given by Darktrace DETECT also enabled the security team to confirm which files had been accessed and were likely part of the data leak.

Figure 6: Example Cyber AI Analyst incident of UserB SaaS Office365 account

Darktrace RESPOND

In this incident, the attackers successfully compromised O365 accounts in order to exfiltrate customer data. Whilst Darktrace RESPOND/Apps was being trialed and suggested several actions, it was configured in human confirmation mode. The following RESPOND/Apps actions were advised for these activities:  

·      ‘Antigena [RESPOND] Unusual Access Block’ triggered by the successful login from an unusual IP address, would have actioned the ‘Block IP’ inhibitor, preventing access to the account from the unusual IP for up to 24 hours
·      ‘Suspicious Source Activity Block’, triggered by the suspicious user agent used to bypass MFA, would have actioned the ‘Disable User’ inhibitor, disabling the user account for up to 24 hours 

During this incident, Darktrace RESPOND/Network was being used in fully autonomous mode in order to prevent the threat actor from pivoting into the network. The security team were unable to conclusively say if any attempts by the attacker to do this had been made. 

Concluding Thoughts  

Data theft extortion has become a widely used attack technique, and ransomware gangs may increasingly use this technique alone to target organizations without secure data encryption and storage policies.  

This case study describes a SaaS data theft extortion incident which bypassed MFA and existing security tools. The attacker appeared to compromise credentials without bruteforce activity, possibly with the use of social engineering through phishing. However, from the first new login, Darktrace DETECT identified the unusual credential use in spite of it being an existing account. Had Darktrace RESPOND/Apps been configured, it would have autonomously responded to halt this login and prevent the attacker from accomplishing their data theft mission.

Thanks to Oakley Cox, Brianna Leddy and Shuh Chin Goh for their contributions.

Appendices

References 

[1] https://securelist.com/new-ransomware-trends-in-2022/106457/

[2] https://www.itpro.co.uk/security/ransomware/367624/the-rise-of-double-extortion-ransomware

[3] https://www.malwarebytes.com/blog/news/2020/10/vastaamo-psychotherapy-data-breach-sees-the-most-vulnerable-victims-extorted

[4] https://www.blackfog.com/shift-from-ransomware-to-data-theft-extortion/

[5] https://www.abuseipdb.com/check/105.112.59.83

[6] https://www.abuseipdb.com/check/105.112.36.212

[7] https://www.abuseipdb.com/check/45.130.83.129

[8] https://docs.microsoft.com/en-us/microsoft-365/compliance/mailitemsaccessed-forensics-investigations?view=o365-worldwide

[9] https://www.abuseipdb.com/check/45.135.187.108

[10] https://www.virustotal.com/gui/ip-address/45.137.20.65/details

[11] https://tidorg.com/new-bec-phishing-attack-steals-office-365-credentials-and-bypasses-mfa/

[12] https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/responding-to-a-compromised-email-account?view=o365-worldwide

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Einblicke in das SOC-Team

PurpleFox in a Henhouse: How Darktrace Hunted Down a Persistent and Dynamic Rootkit

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27
Nov 2023

Versatile Malware: PurpleFox

As organizations and security teams across the world move to bolster their digital defenses against cyber threats, threats actors, in turn, are forced to adopt more sophisticated tactics, techniques and procedures (TTPs) to circumvent them. Rather than being static and predictable, malware strains are becoming increasingly versatile and therefore elusive to traditional security tools.

One such example is PurpleFox. First observed in 2018, PurpleFox is a combined fileless rootkit and backdoor trojan known to target Windows machines. PurpleFox is known for consistently adapting its functionalities over time, utilizing different infection vectors including known vulnerabilities (CVEs), fake Telegram installers, and phishing. It is also leveraged by other campaigns to deliver ransomware tools, spyware, and cryptocurrency mining malware. It is also widely known for using Microsoft Software Installer (MSI) files masquerading as other file types.

The Evolution of PurpleFox

The Original Strain

First reported in March 2018, PurpleFox was identified to be a trojan that drops itself onto Windows machines using an MSI installation package that alters registry values to replace a legitimate Windows system file [1]. The initial stage of infection relied on the third-party toolkit RIG Exploit Kit (EK). RIG EK is hosted on compromised or malicious websites and is dropped onto the unsuspecting system when they visit browse that site. The built-in Windows installer (MSIEXEC) is leveraged to run the installation package retrieved from the website. This, in turn, drops two files into the Windows directory – namely a malicious dynamic-link library (DLL) that acts as a loader, and the payload of the malware. After infection, PurpleFox is often used to retrieve and deploy other types of malware.  

Subsequent Variants

Since its initial discovery, PurpleFox has also been observed leveraging PowerShell to enable fileless infection and additional privilege escalation vulnerabilities to increase the likelihood of successful infection [2]. The PowerShell script had also been reported to be masquerading as a .jpg image file. PowerSploit modules are utilized to gain elevated privileges if the current user lacks administrator privileges. Once obtained, the script proceeds to retrieve and execute a malicious MSI package, also masquerading as an image file. As of 2020, PurpleFox no longer relied on the RIG EK for its delivery phase, instead spreading via the exploitation of the SMB protocol [3]. The malware would leverage the compromised systems as hosts for the PurpleFox payloads to facilitate its spread to other systems. This mode of infection can occur without any user action, akin to a worm.

The current iteration of PurpleFox reportedly uses brute-forcing of vulnerable services, such as SMB, to facilitate its spread over the network and escalate privileges. By scanning internet-facing Windows computers, PurpleFox exploits weak passwords for Windows user accounts through SMB, including administrative credentials to facilitate further privilege escalation.

Darktrace detection of PurpleFox

In July 2023, Darktrace observed an example of a PurpleFox infection on the network of a customer in the healthcare sector. This observation was a slightly different method of downloading the PurpleFox payload. An affected device was observed initiating a series of service control requests using DCE-RPC, instructing the device to make connections to a host of servers to download a malicious .PNG file, later confirmed to be the PurpleFox rootkit. The device was then observed carrying out worm-like activity to other external internet-facing servers, as well as scanning related subnets.

Darktrace DETECT™ was able to successfully identify and track this compromise across the cyber kill chain and ensure the customer was able to take swift remedial action to prevent the attack from escalating further.

While the customer in question did have Darktrace RESPOND™, it was configured in human confirmation mode, meaning any mitigative actions had to be manually applied by the customer’s security team. If RESPOND had been enabled in autonomous response mode at the time of the attack, it would have been able to take swift action against the compromise to contain it at the earliest instance.

Attack Overview

Figure 1: Timeline of PurpleFox malware kill chain.

Initial Scanning over SMB

On July 14, 2023, Darktrace detected the affected device scanning other internal devices on the customer’s network via port 445. The numerous connections were consistent with the aforementioned worm-like activity that has been reported from PurpleFox behavior as it appears to be targeting SMB services looking for open or vulnerable channels to exploit.

This initial scanning activity was detected by Darktrace DETECT, specifically through the model breach ‘Device / Suspicious SMB Scanning Activity’. Darktrace’s Cyber AI Analyst™ then launched an autonomous investigation into these internal connections and tied them into one larger-scale network reconnaissance incident, rather than a series of isolated connections.

Figure 2: Cyber AI Analyst technical details summarizing the initial scanning activity seen with the internal network scan over port 445.

As Darktrace RESPOND was configured in human confirmation mode, it was unable to autonomously block these internal connections. However, it did suggest blocking connections on port 445, which could have been manually applied by the customer’s security team.

Figure 3: The affected device’s Model Breach Event Log showing the initial scanning activity observed by Darktrace DETECT and the corresponding suggested RESPOND action.

Privilege Escalation

The device successfully logged in via NTLM with the credential, ‘administrator’. Darktrace recognized that the endpoint was external to the customer’s environment, indicating that the affected device was now being used to propagate the malware to other networks. Considering the lack of observed brute-force activity up to this point, the credentials for ‘administrator’ had likely been compromised prior to Darktrace’s deployment on the network, or outside of Darktrace’s purview via a phishing attack.

Exploitation

Darktrace then detected a series of service control requests over DCE-RPC using the credential ‘admin’ to make SVCCTL Create Service W Requests. A script was then observed where the controlled device is instructed to launch mshta.exe, a Windows-native binary designed to execute Microsoft HTML Application (HTA) files. This enables the execution of arbitrary script code, VBScript in this case.

Figure 4: PurpleFox remote service control activity captured by a Darktrace DETECT model breach.
Figure 5: The infected device’s Model Breach Event Log showing the anomalous service control activity being picked up by DETECT.

There are a few MSIEXEC flags to note:

  • /i : installs or configures a product
  • /Q : sets the user interface level. In this case, it is set to ‘No UI’, which is used for “quiet” execution, so no user interaction is required

Evidently, this was an attempt to evade detection by endpoint users as it is surreptitiously installed onto the system. This corresponds to the download of the rootkit that has previously been associated with PurpleFox. At this stage, the infected device continues to be leveraged as an attack device and scans SMB services over external endpoints. The device also appeared to attempt brute-forcing over NTLM using the same ‘administrator’ credential to these endpoints. This activity was identified by Darktrace DETECT which, if enabled in autonomous response mode would have instantly blocked similar outbound connections, thus preventing the spread of PurpleFox.

Figure 6: The infected device’s Model Breach Event Log showing the outbound activity corresponding to PurpleFox’s wormlike spread. This was caught by DETECT and the corresponding suggested RESPOND action.

Installation

On August 9, Darktrace observed the device making initial attempts to download a malicious .PNG file. This was a notable change in tactics from previously reported PurpleFox campaigns which had been observed utilizing .MOE files for their payloads [3]. The .MOE payloads are binary files that are more easily detected and blocked by traditional signatured-based security measures as they are not associated with known software. The ubiquity of .PNG files, especially on the web, make identifying and blacklisting the files significantly more difficult.

The first connection was made with the URI ‘/test.png’.  It was noted that the HTTP method here was HEAD, a method similar to GET requests except the server must not return a message-body in the response.

The metainformation contained in the HTTP headers in response to a HEAD request should be identical to the information sent in response to a GET request. This method is often used to test hypertext links for validity and recent modification. This is likely a way of checking if the server hosting the payload is still active. Avoiding connections that could possibly be detected by antivirus solutions can help keep this activity under-the-radar.

Figure 7: Packet Capture from an affected customer device showing the initial HTTP requests to the payload server.
Figure 8: Packet Capture showing the HTTP requests to download the payloads.

The server responds with a status code of 200 before the download begins. The HEAD request could be part of the attacker’s verification that the server is still running, and that the payload is available for download. The ‘/test.png’ HEAD request was sent twice, likely for double confirmation to begin the file transfer.

Figure 9: PCAP from the affected customer device showing the Windows Installer user-agent associated with the .PNG file download.

Subsequent analysis using a Packet Capture (PCAP) tool revealed that this connection used the Windows Installer user agent that has previously been associated with PurpleFox. The device then began to download a payload that was masquerading as a Microsoft Word document. The device was thus able to download the payload twice, from two separate endpoints.

By masquerading as a Microsoft Word file, the threat actor was likely attempting to evade the detection of the endpoint user and traditional security tools by passing off as an innocuous text document. Likewise, using a Windows Installer user agent would enable threat actors to bypass antivirus measures and disguise the malicious installation as legitimate download activity.  

Darktrace DETECT identified that these were masqueraded file downloads by correctly identifying the mismatch between the file extension and the true file type. Subsequently, AI Analyst was able to correctly identify the file type and deduced that this download was indicative of the device having been compromised.

In this case, the device attempted to download the payload from several different endpoints, many of which had low antivirus detection rates or open-source intelligence (OSINT) flags, highlighting the need to move beyond traditional signature-base detections.

Figure 10: Cyber AI Analyst technical details summarizing the downloads of the PurpleFox payload.
Figure 11 (a): The Model Breach generated by the masqueraded file transfer associated with the PurpleFox payload.
Figure 11 (b): The Model Breach generated by the masqueraded file transfer associated with the PurpleFox payload.

If Darktrace RESPOND was enabled in autonomous response mode at the time of the attack it would have acted by blocking connections to these suspicious endpoints, thus preventing the download of malicious files. However, as RESPOND was in human confirmation mode, RESPOND actions required manual application by the customer’s security team which unfortunately did not happen, as such the device was able to download the payloads.

Schlussfolgerung

The PurpleFox malware is a particularly dynamic strain known to continually evolve over time, utilizing a blend of old and new approaches to achieve its goals which is likely to muddy expectations on its behavior. By frequently employing new methods of attack, malicious actors are able to bypass traditional security tools that rely on signature-based detections and static lists of indicators of compromise (IoCs), necessitating a more sophisticated approach to threat detection.  

Darktrace DETECT’s Self-Learning AI enables it to confront adaptable and elusive threats like PurpleFox. By learning and understanding customer networks, it is able to discern normal network behavior and patterns of life, distinguishing expected activity from potential deviations. This anomaly-based approach to threat detection allows Darktrace to detect cyber threats as soon as they emerge.  

By combining DETECT with the autonomous response capabilities of RESPOND, Darktrace customers are able to effectively safeguard their digital environments and ensure that emerging threats can be identified and shut down at the earliest stage of the kill chain, regardless of the tactics employed by would-be attackers.

Credit to Piramol Krishnan, Cyber Analyst, Qing Hong Kwa, Senior Cyber Analyst & Deputy Team Lead, Singapore

Appendices

Darktrace Model Detections

  • Device / Increased External Connectivity
  • Device / Large Number of Connections to New Endpoints
  • Device / SMB Session Brute Force (Admin)
  • Compliance / External Windows Communications
  • Anomalous Connection / New or Uncommon Service Control
  • Compromise / Unusual SVCCTL Activity
  • Compromise / Rare Domain Pointing to Internal IP
  • Anomalous File / Masqueraded File Transfer

RESPOND Models

  • Antigena / Network / Significant Anomaly / Antigena Breaches Over Time Block
  • Antigena / Network / External Threat / Antigena Suspicious Activity Block
  • Antigena / Network / Significant Anomaly / Antigena Significant Anomaly from Client Block
  • Antigena / Network / Significant Anomaly / Antigena Enhanced Monitoring from Client Block
  • Antigena / Network / External Threat / Antigena Suspicious File Block
  • Antigena / Network / External Threat / Antigena File then New Outbound Block

List of IoCs

IoC - Type - Description

/C558B828.Png - URI - URI for Purple Fox Rootkit [4]

5b1de649f2bc4eb08f1d83f7ea052de5b8fe141f - File Hash - SHA1 hash of C558B828.Png file (Malware payload)

190.4.210[.]242 - IP - Purple Fox C2 Servers

218.4.170[.]236 - IP - IP for download of .PNG file (Malware payload)

180.169.1[.]220 - IP - IP for download of .PNG file (Malware payload)

103.94.108[.]114:10837 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)

221.199.171[.]174:16543 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)

61.222.155[.]49:14098 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)

178.128.103[.]246:17880 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)

222.134.99[.]132:12539 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)

164.90.152[.]252:18075 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)

198.199.80[.]121:11490 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)

MITRE ATT&CK Mapping

Tactic - Technique

Reconnaissance - Active Scanning T1595, Active Scanning: Scanning IP Blocks T1595.001, Active Scanning: Vulnerability Scanning T1595.002

Resource Development - Obtain Capabilities: Malware T1588.001

Initial Access, Defense Evasion, Persistence, Privilege Escalation - Valid Accounts: Default Accounts T1078.001

Initial Access - Drive-by Compromise T1189

Defense Evasion - Masquerading T1036

Credential Access - Brute Force T1110

Discovery - Network Service Discovery T1046

Command and Control - Proxy: External Proxy T1090.002

References

  1. https://blog.360totalsecurity.com/en/purple-fox-trojan-burst-out-globally-and-infected-more-than-30000-users/
  2. https://www.trendmicro.com/en_us/research/19/i/purple-fox-fileless-malware-with-rookit-component-delivered-by-rig-exploit-kit-now-abuses-powershell.html
  3. https://www.akamai.com/blog/security/purple-fox-rootkit-now-propagates-as-a-worm
  4. https://www.foregenix.com/blog/an-overview-on-purple-fox
  5. https://www.trendmicro.com/en_sg/research/21/j/purplefox-adds-new-backdoor-that-uses-websockets.html
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About the author
Piramol Krishnan
Cyber Security Analyst

$70 Million in Cyber Security Funding for Electric Cooperatives & Utilities

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22
Nov 2023

What is the Bipartisan Infrastructure Deal?

The Bipartisan Infrastructure Law passed by congress in 2021 aimed to upgrade power and infrastructure to deliver clean, reliable energy across the US to achieve zero-emissions. To date, the largest investment in clean energy, the deal will fund new programs to support the development and deployment of clean energy technology.

Why is it relevant to electric municipalities?

Section 40124 of the Bipartisan Infrastructure Law allocates $250 million over a 5-year period to create the Rural and Municipal Utility Cybersecurity (RMUC) Program to help electric cooperative, municipal, and small investor-owned utilities protect against, detect, respond to, and recover from cybersecurity threats.1 This act illuminates the value behind a full life-cycle approach to cyber security. Thus, finding a cyber security solution that can provide all aspects of security in one integrated platform would enhance the overall security posture and ease many of the challenges that arise with adopting multiple point solutions.

On November 16, 2023 the Office of Cybersecurity, Energy Security, and Emergency Response (CESER) released the Advanced Cybersecurity Technology (ACT) for electric utilities offering a $70 million funding opportunity that aims to enhance the cybersecurity posture of electric cooperative, municipal, and small investor-owned utilities.

Funding Details

10 projects will be funded with application submissions due November 29, 2023, 5:00 pm ET with $200,000 each in cash prizes in the following areas:

  1. Direct support for eligible utilities to make investments in cybersecurity technologies, tools, training, and improvements in utility processes and procedures;
  2. Funding to strengthen the peer-to-peer and not-for-profit cybersecurity technical assistance ecosystem currently serving eligible electric utilities; and
  3. Increasing access to cybersecurity technical assistance and training for eligible utilities with limited cybersecurity resources. 2

To submit for this award visit: https://www.herox.com/ACT1Prize

How can electric municipalities utilize the funding?

While the adoption of hybrid working patterns increase cloud and SaaS usage, the number of industrial IoT devices also continues to rise. The result is decrease in visibility for security teams and new entry points for attackers. Particularly for energy and utility organizations.

Electric cooperatives seeking to enhance their cyber security posture can aim to invest in cyber security tools that provide the following:

Compliance support: Consider finding an OT security solution that maps out how its solutions and features help your organization comply with relevant compliance mandates such as NIST, ISA, FERC, TSA, HIPAA, CIS Controls, and more.

Anomaly based detection: Siloed security solutions also fail to detect attacks that span
the entire organization. Anomaly-based detection enhances an organization’s cyber security posture by proactively defending against potential attacks and maintaining a comprehensive view of their attack surface.

Integration capabilities: Implementation of several point solutions that complete individual tasks runs the risk of increasing workloads for operators and creates additional challenges with compliance, budgeting, and technical support. Look for cyber security tools that integrate with your existing technologies.

Passive and active asset tracking: Active Identification offers accurate enumeration, real time updates, vulnerability assessment, asset validation while Passive Identification eliminates the risk of operational disruption, minimizes risk, does not generate additional network traffic. It would be ideal to find a security solution that can do both.

Can secure both IT and OT in unison: Given that most OT cyber-attacks actually start in IT networks before pivoting into OT, a mature security posture for critical infrastructure would include a single solution for both IT and OT. Separate solutions for IT and OT present challenges when defending network boundaries and detecting incidents when an attacker pivots from IT to OT. These independent solutions also significantly increase operator workload and materially diminish risk mitigation efforts.

Darktrace/OT for Electric Cooperatives and Utilities

For smaller teams with just one or two dedicated employees, Darktrace’s Cyber AI Analyst and Investigation features allow end users to spend less time in the platform as it compiles critical incidents into comprehensive actionable event reports. AI Analyst brings all the information into a centralized view with incident reporting in natural language summaries and can be generated for compliance reports specific to regulatory requirements.  

For larger teams, Darktrace alerts can be forwarded to 3rd party platforms such as a SIEM, where security team decision making is augmented. Additionally, executive reports and autonomous response reduce the alert fatigue generally associated with legacy tools. Most importantly, Darktrace’s unique understanding of normal allows security teams to detect zero-days and signatureless attacks regardless of the size of the organization and how alerts are consumed.

Key Benefits of Darktrace/OT

Figure 1: Darktrace/OT stops threats moving from IT to OT by providing a unified view across both systems

References

1. https://www.whitehouse.gov/briefing-room/statements-releases/2021/11/06/fact-sheet-the-bipartisan-infrastructure-deal/

2. https://www.energy.gov/ceser/rural-and-municipal-utility-advanced-cybersecurity-grant-and-technical-assistance-rmuc

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About the author
Jeff Cornelius
EVP, Cyber-Physische Sicherheit

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